5. INVESTMENT SECURITIES (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax			$ 8,396,000		$ 5,930,000
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax			3,359,000		2,372,000
Proceeds From Sales And Calls Of Available For Sale Securities	2,957,000	9,294,000	8,695,000	10,886,000
Available-for-sale Securities, Gross Realized Gains	$ 1,000	$ 326,000	$ 76,000	$ 353,000
Continuous Loss Position, Additional Information	the Company held 195 securities of which ten were in a loss position for less than twelve months and none were in a loss position for twelve months or more. Of the ten securities in a loss position, nine are mortgage-backed securities and one is a corporate bond. At December 31, 2011, the Company held 189 securities of which eleven were in a loss position for less than twelve months and none were in a loss position for twelve months or more. All eleven securities in a loss position were mortgage-backed securities		the Company held 195 securities of which ten were in a loss position for less than twelve months and none were in a loss position for twelve months or more. Of the ten securities in a loss position, nine are mortgage-backed securities and one is a corporate bond. At December 31, 2011, the Company held 189 securities of which eleven were in a loss position for less than twelve months and none were in a loss position for twelve months or more. All eleven securities in a loss position were mortgage-backed securities